Fusa Furuya, born in July 1897, does not live at the address where she is registered and her whereabouts are unknown, a municipal official said.

He said that they had not personally contacted the two old people for decades, despite their listing as the longest-living in the city.

They made the discoveries when they began updating their records for a holiday in honour of the elderly to be held next month.

Mrs Furuya's 79-year-old daughter told officials she thought her mother was just outside Tokyo with her younger brother, with whom she has lost touch. But that address turned out to be a empty site.

Police are also interviewing the brother and another daughter, but still have not been able to locate Mrs Furuya.

The disappearance follows last week's grisly discovery - also by officials updating the most-elderly list - that the man listed as Tokyo's oldest man, who would have been 111 years old, had actually been dead for 30 years and his decayed body was still in his home.

Police are investigating the family of Sogen Kato for alleged abandonment and swindling his pension money. Mr Kato is believed to have died around 1978 after he had retreated to his bedroom, saying he wanted to be a living Buddha.

Officials said that they had not personally contacted the city's two oldest people for decades.

Authorities are also looking for a 106-year-old man who is missing in Nagoya, central Japan and three more centenarians were unaccounted for in Tokyo.